- Enigma 2 (1984 Zilec Electronics UK) was a conversion applied to a Taito Space Invaders Part II board set. On board is a "Sound System" board plugged into one of the EPROM sockets that contains a CPU, sound ROM, 2 x 2114, an AY PSG and a block of dipswitches (i.e. a cut down Scramble-style sound board).